HP 4GB 2 x 2GB PC2-6400U DDR2 800 Non-ECC Unbuffered Memory Kit 404575-888 Hynix Manufacturer: Hynix HYMP125U64CP8-S6 HP Part Number: 404575-888 Memory Type: 240 Pin DDR2 SDRAM Capacity: 4GB 2 x 2GB Memory Bus Type: PC2-6400U 800